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[SCSI] tgt: use scsi_init_io instead of scsi_alloc_sgtable

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If we export scsi_init_io()/scsi_release_buffers() instead of
scsi_{alloc,free}_sgtable() from scsi_lib than tgt code is much more
insulated from scsi_lib changes. As a bonus it will also gain bidi
capability when it comes.

[jejb: rebase on to sg_table and fix up rejections]

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This commit is contained in:
Boaz Harrosh 2007-12-13 16:14:27 -08:00 committed by James Bottomley
parent 03e7925d07
commit bb52d82f45
3 changed files with 16 additions and 36 deletions
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20
drivers/scsi/scsi_lib.c
View File

@ -746,7 +746,7 @@ static struct scatterlist *scsi_sg_alloc(unsigned int nents, gfp_t gfp_mask)
return mempool_alloc(sgp->pool, gfp_mask);
}
int scsi_alloc_sgtable(struct scsi_cmnd *cmd, gfp_t gfp_mask)
static int scsi_alloc_sgtable(struct scsi_cmnd *cmd, gfp_t gfp_mask)
{
int ret;
@ -762,15 +762,11 @@ int scsi_alloc_sgtable(struct scsi_cmnd *cmd, gfp_t gfp_mask)
return ret;
}
EXPORT_SYMBOL(scsi_alloc_sgtable);
void scsi_free_sgtable(struct scsi_cmnd *cmd)
static void scsi_free_sgtable(struct scsi_cmnd *cmd)
{
__sg_free_table(&cmd->sg_table, SCSI_MAX_SG_SEGMENTS, scsi_sg_free);
}
EXPORT_SYMBOL(scsi_free_sgtable);
/*
* Function: scsi_release_buffers()
*
@ -788,7 +784,7 @@ EXPORT_SYMBOL(scsi_free_sgtable);
* the scatter-gather table, and potentially any bounce
* buffers.
*/
static void scsi_release_buffers(struct scsi_cmnd *cmd)
void scsi_release_buffers(struct scsi_cmnd *cmd)
{
if (cmd->use_sg)
scsi_free_sgtable(cmd);
@ -800,6 +796,7 @@ static void scsi_release_buffers(struct scsi_cmnd *cmd)
cmd->request_buffer = NULL;
cmd->request_bufflen = 0;
}
EXPORT_SYMBOL(scsi_release_buffers);
/*
* Function: scsi_io_completion()
@ -1001,7 +998,7 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
* Returns: 0 on success
* BLKPREP_DEFER if the failure is retryable
*/
static int scsi_init_io(struct scsi_cmnd *cmd)
int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask)
{
struct request *req = cmd->request;
int count;
@ -1016,7 +1013,7 @@ static int scsi_init_io(struct scsi_cmnd *cmd)
/*
* If sg table allocation fails, requeue request later.
*/
if (unlikely(scsi_alloc_sgtable(cmd, GFP_ATOMIC))) {
if (unlikely(scsi_alloc_sgtable(cmd, gfp_mask))) {
scsi_unprep_request(req);
return BLKPREP_DEFER;
}
@ -1036,6 +1033,7 @@ static int scsi_init_io(struct scsi_cmnd *cmd)
cmd->use_sg = count;
return BLKPREP_OK;
}
EXPORT_SYMBOL(scsi_init_io);
static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev,
struct request *req)
@ -1081,7 +1079,7 @@ int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req)
BUG_ON(!req->nr_phys_segments);
ret = scsi_init_io(cmd);
ret = scsi_init_io(cmd, GFP_ATOMIC);
if (unlikely(ret))
return ret;
} else {
@ -1132,7 +1130,7 @@ int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req)
if (unlikely(!cmd))
return BLKPREP_DEFER;
return scsi_init_io(cmd);
return scsi_init_io(cmd, GFP_ATOMIC);
}
EXPORT_SYMBOL(scsi_setup_fs_cmnd);

28
drivers/scsi/scsi_tgt_lib.c
View File

@ -331,8 +331,7 @@ static void scsi_tgt_cmd_done(struct scsi_cmnd *cmd)
scsi_tgt_uspace_send_status(cmd, tcmd->itn_id, tcmd->tag);
if (scsi_sglist(cmd))
scsi_free_sgtable(cmd);
scsi_release_buffers(cmd);
queue_work(scsi_tgtd, &tcmd->work);
}
@ -353,25 +352,6 @@ static int scsi_tgt_transfer_response(struct scsi_cmnd *cmd)
return 0;
}
static int scsi_tgt_init_cmd(struct scsi_cmnd *cmd, gfp_t gfp_mask)
{
struct request *rq = cmd->request;
int count;
cmd->use_sg = rq->nr_phys_segments;
if (scsi_alloc_sgtable(cmd, gfp_mask))
return -ENOMEM;
cmd->request_bufflen = rq->data_len;
dprintk("cmd %p cnt %d %lu\n", cmd, scsi_sg_count(cmd),
rq_data_dir(rq));
count = blk_rq_map_sg(rq->q, rq, scsi_sglist(cmd));
BUG_ON(count > cmd->use_sg);
cmd->use_sg = count;
return 0;
}
/* TODO: test this crap and replace bio_map_user with new interface maybe */
static int scsi_map_user_pages(struct scsi_tgt_cmd *tcmd, struct scsi_cmnd *cmd,
unsigned long uaddr, unsigned int len, int rw)
@ -397,9 +377,11 @@ static int scsi_map_user_pages(struct scsi_tgt_cmd *tcmd, struct scsi_cmnd *cmd,
}
tcmd->bio = rq->bio;
err = scsi_tgt_init_cmd(cmd, GFP_KERNEL);
if (err)
err = scsi_init_io(cmd, GFP_KERNEL);
if (err) {
scsi_release_buffers(cmd);
goto unmap_rq;
}
return 0;

4
include/scsi/scsi_cmnd.h
View File

@ -127,8 +127,8 @@ extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
size_t *offset, size_t *len);
extern void scsi_kunmap_atomic_sg(void *virt);
extern int scsi_alloc_sgtable(struct scsi_cmnd *, gfp_t);
extern void scsi_free_sgtable(struct scsi_cmnd *);
extern int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask);
extern void scsi_release_buffers(struct scsi_cmnd *cmd);
extern int scsi_dma_map(struct scsi_cmnd *cmd);
extern void scsi_dma_unmap(struct scsi_cmnd *cmd);